Transition Culture

6 Feb 2007

When Double Glazing Goes Horribly Wrong…

Double glazed windows work because they had a vacuum between the two panes of glass (or three if you are fortunate enough to have triple glazed windows) which stops the heat passing between the two. Energy advice books will often tell you to keep an eye on your double glazed units, if condensation starts to appear between the panes, it is an indicator that the vacuum has gone, that the window is doing very little in terms of energy efficiency, and it needs to be replaced (seeing dead flies or childrens’ toys in there indicates the same…). As I returned on the train the other day from doing a talk in Penzance (for Transition Penwith, a very vibrant bunch…), I noticed that the window next to me was the next step on, a great example of how to tell when you should have replaced your double glazed unit about 4 years ago.

It was very impressive. The space between the two panes of glass contained about 4 inches of water. Each time the train started to go up a hill the water would slosh down to one end, sloshing back again when the train went downhill again (see right). It was very diverting, although strictly speaking not best practice from an energy efficiency point of view. Of course it may have been deliberate. First Great Western Trains may be planning to keep small fish in the gap, in order to give people something entertaining and relaxing to look at while their train is broken down in a siding outside Reading for 4 hours. A bit like painting psychiatric hospitals pastel pink to calm everybody down a bit, perhaps fish tank windows are the new policy for preventing ‘rail rage’.

Anyway, the point of this somewhat pointless post is that if you have double glazing, and the space between you glass contains 4 inches of water, you should really think about having them replaced. Or make a statement of it and get some fish in there. Or tiny remote controlled submarines (I’m sure you’d find some on Ebay), which could keep you amused for hours. Or perhaps some kind of worm bin type thing like we made in school as children where you can watch the worms burrowing through the organic matter (although this might make your room a bit dark). It is also clear that if you have such windows you are probably the kind of person who leaves things until the last minute, never a very good trait, especially as that appears to be humanity’s collective response to climate change. The advice for someone with misted up double glazing units is the same for a species living on a planet experiencing the warmest year on record and with melting icecaps, time to get it sorted out…